Kenwood KR-750 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 13th April 2005, 02:44 AM   #1
diyAudio Member
Brian Donaldson's Avatar
Join Date: Jan 2003
Location: Texas, Love it or leave it
Default Kenwood KR-750

Ok, I bought a unique Kenwood reciever on Ebay that didn't work for $5. I have a working model I bought new, and still have. It's a really nice sounding reciever for early 80's Japanese.

Anyway, I opened it up and it had tin foil over the fuse and one of the outputs had a big black hole in it, so I set it aside. Then I found a new set of outputs on Ebay, So I started poking around. I cut the dead pair of outputs out so the protection circiut would let it power up and see if the other channel worked. The funny thing is they both now work, although the channel without output transistors badly distorts if you put any volume to it.

Just from following traces, it seems to be a CF output Shitklai pair and the pre driver first transistor of the pair is feeding the output, although greatly current limited. My question is ... Does this mean that the only problem is likely the blown outputs?. I'm afraid of just throwing a new set of these not so easy to find original manufactured (not crappy counterfit NTE garbage) outputs in just to have some bad Vbe diode stack blow them or something. I'll check and adjust the bais of course, and bring it up with my variac, but a little reasurance would help.

Another weird thing, this has 50V rails at the outputs, but it's only rated at 60W @ 8 ohms RMS. That's a lot of waisted voltage for an amp that only needs to put 32V peaks. Maybe it helps keep everything in the linear region and helps it sound good.

If any of you wise old tecks can advise, I would be greatfull
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
kenwood kac-715 purocolt Car Audio 6 16th May 2014 10:23 PM
Help with Kenwood KA-94 lumstar Solid State 0 7th January 2009 12:31 AM
Kenwood L-07D... bulgin Analogue Source 0 14th July 2007 07:18 PM
Which dac has this Kenwood? tubee Digital Source 5 22nd August 2006 07:34 PM
kenwood vr 309 v1d9uy Subwoofers 0 8th January 2006 01:48 PM

New To Site? Need Help?

All times are GMT. The time now is 05:48 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2